1. What is CNC Feed Rate?

Feed rate is the velocity at which the cutter is fed, that is, advanced against the workpiece. It is measured in units of distance per revolution for turning and boring (typically inches per revolution [ipr] or millimeters per revolution). For milling, it is expressed in units of distance per time for milling (typically inches per minute [ipm] or millimeters per minute).

2. How Does the Calculator Work?

The calculator uses the feed rate formula:

Where:

• \( Chip Load \) — The amount of material removed by each cutting edge during a revolution (in/tooth)
• \( RPM \) — Rotations per minute of the spindle
• \( Flutes \) — Number of cutting edges on the tool

Explanation: The formula calculates how fast the cutting tool should advance through the material based on tool specifications and spindle speed.

3. Importance of Feed Rate Calculation

Details: Proper feed rate calculation is crucial for achieving optimal machining results, including surface finish, tool life, and machining efficiency. Incorrect feed rates can lead to tool breakage, poor surface finish, or inefficient machining.

4. Using the Calculator

Tips: Enter chip load in inches per tooth, RPM in revolutions per minute, and number of flutes. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is chip load and how is it determined?
A: Chip load is the thickness of material removed by each cutting edge. It's determined by the material being cut, tool material, and cutting conditions. Manufacturers typically provide recommended chip loads for their tools.

Q2: How does feed rate affect tool life?
A: Both too high and too low feed rates can reduce tool life. Too high feed rates cause excessive heat and tool wear, while too low feed rates can cause rubbing instead of cutting, leading to premature tool failure.

Q3: Can I use this calculator for metric units?
A: This calculator uses imperial units (inches). For metric calculations, you would need to convert chip load to mm/tooth and the result will be in mm/min.

Q4: How does material hardness affect feed rate?
A: Harder materials typically require lower feed rates to prevent excessive tool wear and breakage, while softer materials can handle higher feed rates.

Q5: Should I always use the calculated feed rate?
A: The calculated feed rate is a starting point. Always consider machine capability, tool condition, workpiece setup, and make adjustments based on actual cutting conditions and results.